The strict limitations of the constrained, sloping site also demanded an efficient layout. Thus, the design uses a simple and economical configuration whose formal language is both functional and expressive. The helical concrete structure is organized around a central elliptical element that forms a light well. The concrete framework anchors rhythmically overlapping steel screens that appear to float nimbly along the exterior. Vines trained onto the screens provide living green walls, allowing the building to recede into the hillside and acquire a modern-ruin character.

Rather than dedicate a large portion of the limited site to satisfy Austin’s water collection and impervious cover requirements, the structure accommodates a planted green roof that acts as a water detention pond. This feature allows for an increased square footage overall to meet parking requirements while mitigating the visual impact of the structure to the adjacent neighborhood and creating a potential habitat for native vegetation and birds. This facility achieves maximum function and architectural expression while optimizing durability and minimizing maintenance through a restrained material palette.

Three basic elements — concrete, steel screens, and vegetation — perform together to transform the experience into one of drama, dappled natural light, greenery, and free flowing breezes. The efficiency of the continuous helical structure allows removal of material in the four exterior corners and central core, reducing the total volume of concrete used. Steel screens clad the building and provide security with significantly less material volume and weight. A facade of living vegetation filters the harsh Texas sunlight and obviates the need for additional materials and finishes.

Above the parking deck, the concrete structure integrates a water detention pond containing a planted green roof. This solution saves a significant portion of the site from being dedicated — effectively lost — to water detention.